Measurements of the liquid height upstream from an obstruction placed in an open-channel flow can be used to determine volume flow rate. (Such obstructions, designed and calibrated to measure rate of open-channel flow, are called weirs.) Assume the volume flow rate, \(Q\), over a weir is a function of upstream height, \(h\), gravity, \(g\), and channel width, \(b\). Use dimensional analysis to find the functional dependence of \(Q\) on the other variables.